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Friday, May 8, 2015

Captain FitzRoy knew best!

Robert Fitzroy (1805-1865), Captain of HMS Beagle, is a famous personage. He's mainly famous by association with his one-time very famous passenger, the naturalist Charles Darwin on the famous voyage to map the coastline of South America. Fitzroy was a prominent Royal Navy officer who held many other positions during his career, but he is most widely known for his religious fundamentalism and opposition to Darwin's heretical theory of evolution by natural selection.

Among other things, it was Fitzroy who had gathered a collection of Galapagos finches, that some years after the return to England, Darwin asked to borrow so that he could help flesh out his evolutionary ideas in ways that are now quite famous. Fitzroy bitterly resented that he had helped Darwin establish this terrible idea about life.

FitzRoy has paid the price for his stubborn biblical fundamentalism, a price of ridicule. But that is quite unfair. Fitzroy was a sailor and his hydrographic surveys of South America on the Beagle were an important part of the Navy's desire to understand the world's oceans. His meticulous up-and-down, back-and-forth fathoming of the ocean floor and coastline gave Darwin months of free time, to roam the adjacent territory in South America, doing his own kind of geological surveying, that led him to see physical and biogeographic patterns that accounted for the nature and origin of life's diversity. That it was heretical to biblical thought was not Darwin's motive at the time, nor is it unreasonable to think that a believer, like FitzRoy, should easily accept this challenge to the meaning of existence lightly.

But FitzRoy, who went on to other distinguished positions in the British government, made a contribution perhaps more innovative and at least as important as his hydrographic surveys: he was the pioneer of formal meteorology, and of weather forecasting.

This contribution of FitzRoy's is important to me, because I was at one time a professional meteorologist (and, indeed, in Britain). FitzRoy developed extensive material on proper weather-measuring instrumentation (weather vanes, thermometers, barometers), and ways of collecting and analyzing meteorological data. His main objective was the safety of sailors and their ability to anticipate and avoid dangerous weather.

FitzRoy's work led to the systematic collection of weather data, the systematic understanding of the association of storms with pressure and temperature changes, the large-scale flow of air and its weather implications. And he considered the nature of the sorts of data that, in the 1800s, could be collected. He developed some basic forecasting rules based on these sorts of data, understood the importance of maps plotting similar observations over large areas and what happened after the time of the map, and of global wind, weather, and pressure patterns, among other things.

Cover page of FitzRoy's book. Google digitization from UCalifornia

In 1863, just four years after Darwin had made a big stir with his Origin of Species, then Rear Admiral FitzRoy wrote a popular book, such as things were at the time, called The Weather Book: A Manual of Practical Meteorology. This is a very clearly written book that shows the state of this new science at the time. It was an era of inductionism--the wholesale collection of lots and lots of data--based on the Enlightenment view that from data laws of Nature would emerge. But FitzRoy, a meticulous and careful observer and thinker, also noticed something important. As he wrote in The Weather Book:

Objects of known importance should take precedence of any speculative or merely curious observations. However true may be the principle of accumulating facts in order to deduce laws, a reasonable line of action, a sufficiently apparent cause for accumulation, is surely necessary, lest heaps of chaff or piles of unprofitable figures should overwhelm the grain-seeker, or bewilder any one in his search after undiscovered laws.

Definite objects, a distinct course, should be kept in mind, lest we should take infinite pains in daily registration of facts scarcely less insignificant for future purposes than our nightly dreams.

Does this perhaps ring any relevant bells about what is going on today, in many areas of science, including a central one spawned by Mendel: genetics? Maybe we should be paying a bit more heed, rather than ridicule, to another of our Victorian antecedents.

Yes, I'm taking impish advantage of a fortuitous quote that I came across, to make a point. But it is a valid point in today's terms nonetheless, when anything one chooses to throw in the hopper is considered 'data' and applauded.

In fact, modern meteorology is a field in which huge amounts of data collection are, indeed, quite valuable. But there are legitimate reasons: first, patterns repeat themselves and recognizing them greatly aids forecasting, both locally and on a continental scale; second, we have a prior theory, based on hydrodynamics, into which to fit these data. Three, using the theory and the data from the past and present, we can reasonably accurately predict specific future states. These are advantages and characteristics hardly shared with anything comparably rigorous in genetics and evolution, where, nonetheless, raw and expensive inductionism prevails today.

5 comments:

The meteorology:evolutionary biology analogy is an interesting one. I can see it being taken further - meteorologists have collected tons of data and can now model weather patterns on a long term (ie climate change) and short term (ie your weekly forecast) basis with great accuracy. But they still can't tell you if a catastrophic storm will hit Tampa this year, or why my town was decimated by a tornado but your seemingly identical town just down the road was spared. So the long- and middle-range theory is there, but predicting important, one-off events remains elusive. Similarly, we understand a lot about how genetics and evolution works, but can't predict or explain precisely who will get what type of cancer, why human bipedalism evolved, or why Doc Watson was a guitar genius. We have a good handle on relative probabilities and can explain the 'how' of the matter after the fact, but the 'why' and 'when will it happen next' remain utterly elusive.

If there are fundamental, inescapable limits to what can be known about the weather - Is it even possible to know with real certainty if Tampa will get hit with a major hurricane this year? Next year? - are there similar limits to understanding similarly complex systems like genotype:environment:phenotype?

Herman, Very nice to hear from you!In my view, local forecasts still have a lot to be desired, even just 24-hour ones, when things are unsettled. I used to work in the UK, when everything was often close to the 'tipping points'. Forecasting was like playing the horses!

Most commercial services, I've been told, basically use large-scale models based on theory and historical data (inductionism), but don't really take local details into account. Most local forecasters, such as on TV, just repeat the national forecasts.

To me, the important thing is to acknowledge limitations and not puff up one's claims to insight or power. In meteorology, at least, there is extensive theory from physics to help. In genetics, and its evolutionary aspects as well, the theory is very generic and not at all the same kind of organizing knowledge.

Indeed, I'd say that physics is about truly replicable processes of interaction, whereas evolution and hence genetics are about accumulating differences--things that don't replicate.

That's just my take on things, but clearly we are far from an adequate understanding of those details of life, but just as far from acknowledging what we don't know. Instead, we plead for more inductionism, because it's safe to do that (grant-wise); thinking deeper is much harder and, of course, only a small percentage of us are really capable of that, as I think history shows.

That sounds negative so, along with your final sentence, I'd say there's a great positive: Limits to understanding make life far more fun and interesting.

Herman, I certainly agree with your general point. I would only add that I'm not sure what it means to have a good handle on probabilities. We know the fraction of the time that given X conditions, Y has happened. This is true for weather as well as genetics or epidemiology. We treat this as a probability, useful for prediction, but I'm still stuck on what 10, 20, 30% probability of getting a disease means, when everyone is unique, and we either do or don't get the disease. We certainly are good at retrodicting events, just not so good at predicting, based on the idea of probabilities.

The quotation from Fitzroy has a pleasing counterpart in a letter from Darwin to Henry Fawcett (1861):

About thirty years ago there was much talk that geologists ought only to observe and not theorise; and I well remember some one saying that at this rate a man might as well go into a gravel-pit and count the pebbles and describe the colours. How odd it is that anyone should not see that all observation must be for or against some view if it is to be of any service!

Reply to David Evans:Thanks much for the quote. There were diverse ideas, and self-descriptions among scientists in Darwin's time, including by Darwin himself on the nature of induction vs fitting a preconceived theory. I didn't know of this quote, but in 2012 wrote one of my Evolutionary Anthropology column installments on this issue: Evolutionary Anthropology 21:131–135 (2012), 'To understand the baboon'. You might find that interesting.

I'll now have to file away the quote you sent, because it will have its future uses!

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